As for an automatic lifting and lowering device for a toilet seat or a toilet cover of a Western-style toilet, a technology disclosed in Unexamined Japanese Patent Publication No. Hei 11-216083 is known, in which each of the toilet seat and the toilet cover is provided with the separate automatic lifting and lowering device. In the automatic lifting and lowering device, an output shaft of a drive motor is coupled with a rotating shaft thereof through a plurality of gear trains so that the output shaft and the rotating shaft are formed nonconcentrically from each other.
The foregoing device requires a large attachment area (with respect to a plane of projection orthogonal to the center of the rotating shaft) because the device has the plurality of gear trains each of which has a different shaft. Thus, the device is inconvenient to use in a toilet seat provided with a function of washing a body with hot water or the like, which is required to be reduced in size and weight.
Considering the foregoing conventional problem, an object of the present invention is to reduce the size, weight, and the like of each of an automatic lifting and lowering device for a toilet seat and an automatic lifting and lowering device for a toilet cover.